Geochemical processes of formations of red-bed associated Cu-Co deposit at Kamoto, Zaire
In the stratiform Cu-Co deposit at Kamoto, ore minerals occur in layers conformable to bedding, or as replacement of nodular and/or bedded dolomite within marine to littoral sediments overlying a thick continental red-bed sequence. delta/sup 13/C and delta/sup 13/O values of more than 70 dolomite samples from the red-bed, ore zone and unmineralized hangingwall sediments were determined to be -9 to +3 per thousand (PDB) and + 7 to +24 per thousand(SMOW), respectively. The delta/sup 13/C values correlate negatively with the amount of relict organic matter in the samples. Poor correlation between delta/sup 13/C and delta/sup 18/O indicates that dolomitization incorporating oxidized organic carbon occurred through a large temperature range. delta/sup 34/S values of about 70 ore sulfide samples range from -15 to +17 per thousand (CDT), correlating positively with both total S content of the samples and the delta/sup 13/C of associated dolomite. The isotopic data, the overgrowth and replacement textures observed among ore and gangue minerals, and the results of thermochemical calculations on the solubility and stability of the sulfides suggest that: (1) less than 30% of the sulfide sulfur in the deposit was fixed as bacteriogenic pyrite during early diagenesis; and (2) the Cu and Co sulfides were formed by later reaction between Cu-, Co- and SO/sub 4/-bearing hot (50-200/sup 0/C.) brines and the diagenetic pyrite, augmented by additional sulfate reduction through organic matter oxidation.
- Research Organization:
- Pennsylvania State Univ., University Park (USA)
- OSTI ID:
- 6196953
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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CARBONATE ROCKS
DIAGENESIS
HYDROTHERMAL ALTERATION
COBALT ORES
CHEMICAL COMPOSITION
MINERALIZATION
PETROGENESIS
COPPER ORES
ZAIRE REPUBLIC
CARBON 13
GEOCHEMISTRY
HYDROTHERMAL SYNTHESIS
ISOTOPE RATIO
MINERALOGY
OXYGEN 18
PETROLOGY
PYRITE
QUANTITATIVE CHEMICAL ANALYSIS
SULFUR CONTENT
AFRICA
CARBON ISOTOPES
CHALCOGENIDES
CHEMICAL ANALYSIS
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EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GEOLOGY
IRON COMPOUNDS
IRON SULFIDES
ISOTOPES
LIGHT NUCLEI
MINERALS
NUCLEI
ORES
OXYGEN ISOTOPES
ROCKS
SEDIMENTARY ROCKS
STABLE ISOTOPES
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
580300* - Mineralogy
Petrology
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580400 - Geochemistry- (-1989)